The process of mixing a substrate with a catalyst for driving a chemical reaction to transform the substrate from a liquid to a solid is well known in the art. The various substrates and catalysts used are numerous and extremely variable in both chemistry and in application. Examples of substrates are those used in thermoplastic and thermoset reactions. In these reactions a liquid polymer is chemically and physically transformed into a solid polymer. The characteristic of a thermoplastic material is that it will melt when sufficiently heated. Thermoset materials when heated will, instead, undergo oxidative destruction before melting.
Whether the end product is thermoplastic or thermoset will depend on the chemistry of the substrate and catalyst used. The presence or absence of cross-linking from one polymeric chain to another essentially dictates whether the end product will be a thermoplastic or a thermoset. The substrate chemistry will also control whether the end product will be rigid, pliable, or elastomeric or rubbery.
The reaction converting a liquid plastic to a solid plastic is often enhanced by the addition of a catalyst. Many polymerization reactions transforming a liquid plastic to a solid plastic will occur in the absence of a catalyst, but the reaction is sufficiently slow as to be negligible in most circumstances. The addition of a catalyst substantially increases the reactive rate if not actually also contributing to the structural form of the final product. The type of catalyst is also quite variable. Catalytic activity may also involve using heat; electromagnetic radiation such as infrared, visible, or ultraviolet energy for initiating a reaction; dark reactions; as well as reactions where just adding the catalyst begins the chemical reaction which is usually exothermic in nature and is self-sustaining to completion.
The specific nature and characterization of these numerous reactions and end products is beyond the scope of this discussion. The single common characteristic inherent to all of these reactions is the essential and necessary mixing together of one component with another in order to begin the polymerization process resulting in an end product. Examples of these reactions are well known even to the general population, and are readily apparent in many household items. For instance, epoxy glues and cements are commercially available and purchased in two containers, providing for directions on mixing, usually in equal parts, the contents from the two containers, then applying the mixture to a work surface, and finally, allowing sufficient time for the epoxy glue to set. The epoxy glue compounds are stored in separate containers and the mixing procedure and application step are left to the purchaser to perform at the time of use.
Another example may be found in the field of dentistry, specifically the methods used to obtain dental impressions. Here, a substrate and catalyst are mixed together to form a paste like compound which is then impressed over the teeth, allowed to solidify, and then removed. This particular end product is chosen for its rubber like characteristics as well as its flow characteristics for obtaining dental impressions. As in all of the above noted reactions, the substrate material and catalyst are brought out of their respective storage containers, mixed together in another vessel by the dentist or dental assistant and then applied to the patient's dentition.
This mixing step can be quite cumbersome to use as well as messy and wasteful of the material. Often times the mixing step requires supplying additional mixing vessels and instruments separate from the storage containers the compounds are stored in. Just as in the epoxy glue that is commercially available in hardware stores, the two compounds are purchased and stored in separate containers, but when needed for use, appropriate amounts of the substrate and catalyst are extruded onto a surface and physically mixed by the end user prior to application. The application process additionally requires other instruments or tools by the end user to apply the mixed substrate and catalyst to the working surface in a timely fashion so as to complete the application process prior to solidification of the mixture.
The storage of the compounds, the mixing of the compounds, and the application of these compounds are carried out in three separate and distinct steps. An apparatus that provided for storage, mixing and application within a single device would provide decided advantages. The present method of providing separate storage mixing and application containers and utensils is not cost efficient and often times is wasteful of the materials.